The lifetime of nitrogen oxides (NO x ) affects the concentration and distribution of NO x and the spatial patterns of nitrogen deposition. Despite its importance, the lifetime of NO x is poorly constrained in rural and remote continental regions. We use measurements from a site in central Alabama during the Southern Oxidant and Aerosol Study (SOAS) in summer 2013 to provide new insights into the chemistry of NO x and NO x reservoirs. We find that the lifetime of NO x during the daytime is controlled primarily by the production and loss of alkyl and multifunctional nitrates (ΣANs). During SOAS, ΣAN production was rapid, averaging 90 ppt h −1 during the day, and occurred predominantly during isoprene oxidation. Analysis of the ΣAN and HNO 3 budgets indicate that ΣANs have an average lifetime of under 2 h, and that approximately 45 % of the ΣANs produced at this site are rapidly hydrolyzed to produce nitric acid. We find that ΣAN hydrolysis is the largest source of HNO 3 and the primary pathway to permanent removal of NO x from the boundary layer in this location. Using these new constraints on the fate of ΣANs, we find that the NO x lifetime is 11 ± 5 h under typical midday conditions. The lifetime is extended by storage of NO x in temporary reservoirs, including acyl peroxy nitrates and ΣANs.